by Erica DeMeritt (Nov, 2018)
Our topic this month was Plate Tectonics. Erica DeMeritt was our presenter. Thank you very much Erica, for the wonderful program. We learned how the earth moves and what happens when it does. The earth’s crust is a not quite connected, crazy quilt of huge pieces or plates, dozens of miles thick. These plates are constantly pushing and shoving and bumping and scraping and pulling apart and jamming together. Each plate is attached to a piece of the Earth’s Upper Mantel and together they ride on the outer core which is made of molten metal. Heat from the inner core and lower mantel cause currents of oozing rock in the lower mantel to slowly rise and fall moving the plates above. Most of this action occurs at the seams or cracks where the plates meet.
But the best part was using a Milky Way candy bar as a model. We learned about Divergent Boundry, by pushing up in the middle of the candy bar. This made cracks in the top layer of the candy bar (earth’s crust) which would then allow magma to rise up and fill in the “hole”.
To create a Convergent Boundary we pushed in from the ends of the candy bar to force the plates together. This will form mountains or one layer will subduct under the other one.
To create a Transform Boundary we placed our fingers on the long edges of the candy bar and moved our right hand forward and our left had back. This can sometimes cause a landslide or an earthquake or just make the ground shake.
We had 16 children and they were all interested in the topic and asked questions. Must be the candy and the yummie snacks.
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